This morning I found that the garage door opened after my wife left and found that it was because the door was currently closing completely and then opening again. I went through the standard steps of checking for obstructions and adjusted the downward force but found that it was already close to the maximum value and moved it to that small amount, but that did not fix the problem. I also tried reducing the cable tension by adjusting the nuts. As a result of unsuccessful attempts at repair, I had to contact the artisans of doorsdirect2u.co.uk, who replaced my gate.